Continuous rotary filter



Dec. 31, 1957 D. RICHARDS commuous ROTARY FILTER Filed Sept. 10, 1954 INV EN TOR. DW/GHT- R/C/MRDS 'CONTINUOUS ROTARY FILTER- Dwight Richards,Orinda, Califl, assignor, by mesne assignments, to Dorr-OliverIncorporated, Stamford, Conn., a corporation of Delaware ApplicationSeptember 10, 1954, Serial No. 455,255

1 Claim. (Cl. 210390) This invention relates to and in general has forits .object the provision of a hermetically sealed rotary table type offilter.

In many instances, it is desirable totally to enclose a continuousrotary table filter in order to prevent the egress of gases therefromand although equipment of this character is not generally new, thesealing means presently rcsorted to is not entirely satisfactory for itinvolves effecting a seal between two relatively moving parts.

More specifically, it is the object of this invention to so construct acontinuous rotary table type of filter that the filter per se can besealed completely within its casing by the use of simple packing betweenthe casing and its hood and by the use of a flexible diaphragm betweenthe casing and a stationary portion of the filter valve.

The invention possesses other advantageous features, some of which, withthe foregoing, will be set forth at length in the following descriptionwhere that form of the invention which has been selected forillustration in the drawings accompanying and forming a part of thepresent specification, is outlined in full. In said drawings, one formof the invention is shown, but it is to be understood that it is notlimited to such form, since the invention as set forth in the claims maybe embodied in other forms.

Referring to the drawing, the single figure therein shown is a verticalmid-section of a continuous rotary table type filter embodying theobjects of my invention.

The filter illustrated in this figure includes a generally cylindricalcasing 1 provided at its lower end with a flat annular bottom 2. Weldedto the inner circular edge of the bottom 2 is an upstanding inner rim 3and welded to the upper edge of this rim is an inwardly extending flange4. Sealed to the upper edge of the casing 1 is an inward ly extendingplate 5 and welded to the upper face thereof is an upwardly extendingcylindrical collar 6 provided with an outwardly extending flange 7.

Disposed over the cylindrical casing above described is an upwardlydished cover 8 provided with a peripheral flange 9 arranged to overlieboth the flange 7 and the upper protruding edge 11 of the collar 6.Formed in the lower face of the flange 9 in vertical registration withthe circular edge 11 is an annular channel 12 and disposed in saidchannel is a body of packing 13. Drilled in the mating flanges 7 and 9are vertically aligned, peripherally spaced bolt holes 14 and 15 andextending through each such pair of vertically aligned holes is a holddown bolt 16. It should here be noted that since the upper edge 11 ofthe collar 6 protrudes above the level of the upper face of the flange7, the edge 11 will be pressed into scaling engagement with the packing13 when the bolts 16 are drawn tight, the packing 13 being forced intosealing engagement with the flange 9 by this same expedient.

Mounted on the annual bottom 2 of the casing 1 is a lower ball race'21arranged to accommodate bearing balls 22 and supported on the balls 22is an upper ball race 23 mounted on a pair of rings 24. Welded to andsupported by the rings 24 is a dished filter pan 25 which although notshown is divided by a plurality of radially extending atentQ divisionstripes into a circular series of sector-shaped filtrate-compartments26.' Formed integral with the pan 25, is. a central annular filtrate.port plate 27 provided with a ring-of ports 28, there being onesuchfport within the confines of "each filtrate compartment 26. Sealedagainst the lower face of the plate 27 is an annular wear plate 29provided with filtrate ports 31 in registration with the ports 28, saidwear plate being bolted to the port plate 27. Seated on the lower faceof wear plate 29 is a stationary valve body 32 provided with suction andblow back chambers 33 over which the filtrate ports 31 of the wear plate29 rotate and thus establish communication successively between each ofthe filtrate compartments 26 of the filter pan and suitable sources ofsubatmospheric pressure and blow back pressure. For this purpose, thevalve body 32 is provided with a cylindrical skirt 34 and with a conduit35, communicating with each of the chambers 33 and arranged to beconnected through a flange 36 with a flexible conduit 37. The details ofconstruction of the filter pan and automatic filter above described areall in accordance with well known practice and in and of themselvesinvolve known invention.

Welded to the cylindrical skirt 34 intermediate its ends andsubstantially at the level of the flange 4 is an annular flange 38 andbridging these two flanges and sealed there to is a flexible watertightannular diaphragm 39. It will be seen that as a result of thisconstruction, the diaphragm 39 forms a very simple and effectivewatertight seal between the filter casing 1 and the valve body 32 which,although referred to as being stationary in the sense that it has norotary motion, nevertheless may wobble to some extent, for in accordancewith standard construction, the valve body 32 must be biased against thewear plate so as to be substantially sealed thereto. Furthermore, thediaphragm 39 obviates the use of a running seal at this point.

The diaphragm 39 then, together with the packing 13, serves effectivelyto seal the entire filter within the filter casing and thus to avoid theegress of gases therefrom and the ingress of air thereinto.

Although not pertinent to the present invention and merely by way ofexplanation, it is to be noted that the structure illustrated in thedrawing immediately above the filtrate compartments 26 of the annularfilter pan 25 constitutes the radially extending stationary cyclindricalcasing of a conventional scroll discharger. Dischargers of this typeinclude a rotating scroll disposed in the path of the cake formed andcarried on the filter medium of the filter and arranged to cut the cakefrom the filter medium and to advance it radially outward and over thelip of the filter pan (25) into a discharge chute such asdiagrammatically indicated on the left side of the present drawing.Although a scroll type of discharger has been indicated in the drawings,as above stated, it is not pertinent to the present invention andvarious other types of dischargers can be substituted therefor.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

A totally enclosed continuous rotary filter comprising: a filter pan; asectionalized rotatable filter unit mounted within said pan for rotationtherewith; a ported valve member fixed to said unit for rotationtherewith; a stationary valve body arranged to register with said valvemember, said valve member having a running watertight fit with saidstationary valve body; a filter casing surrounding said filter andprovided with an opening through which a portion of said valve bodyextends with substantial positive clearance; and a flexible watertightdiaphragm completely bridging said clearance and being sealed to saidvalve body and casing.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Solvay Sept. 24, 1901 Desaulles June 3,1902 Oliver Mar. 30, 1920 Werely Aug. 30, 1921 Stewart July 20, 1926Sweetland Aug. 26, 1930 4 McNeal Oct. 6, 1931 Lee June 27, 1944 LittleOct. 13, 1953 Becker Aug. 31, 1954 FOREIGN PATENTS Germany July 19, 1950France Dec. 12, 1941 Great Britain Oct. 25, 1950

